Package containers of the single use disposable type for food products are often produced from a packaging material. Such packaging material may include paperboard or carton, but may also just contain different plastic layer or metalized film layers. Consequently different kind of food products, like liquid, semi-liquid or solid food products can be stored in such containers.
One example is related to a simple bag, which can contain several plastic layer sealed together to form a bag like shape in order to store for example potato chips, candy or other solid food products. Some other containers are suitable for aseptic packaging of liquid foods such as milk, fruit juices etc, marketed and sold for long term ambient storage. The packaging material in such package container is typically a laminate comprising a bulk layer of paper or paperboard, outer, liquid-tight layers of thermoplastics, a gas barrier layer, most commonly an aluminum foil and finally one or more inside layers composed of one or several part layers, comprising heat-sealable adhesive polymers and/or heat-sealable polyolefins.
Package containers are normally produced and filled on fully automatic packaging machines. In one example, a continuous tube is formed from the web-fed packaging material (said material can include carton based material, but pure plastic laminate may also be suitable); the web of packaging material is sterilized in the packaging machine, and the sterilized web of packaging material is maintained in a closed, sterile environment in the subsequent step. The web is folded and sealed longitudinally to form a vertical tube. The tube is filled with the sterilized or sterile-processed food product, and is sealed and subsequently cut along equally spaced cross sections to form pillow packs, which are then folded mechanically to form respective finished, e.g. substantially parallelepiped-shaped, package containers.
Commonly, the package container have an opening device in order to facilitate consumer opening, many different types of opening devices including pull-tabs or molded opening devices, as for example discussed in WO03/09519925 and WO2009/000927.
However, the latter type of package is a high-volume (in terms of packages per time unit) and low-cost package (due to the properties of the packaging material), and such opening devices might hamper the production speed and be detrimental for the cost of the package.
For this reason there is a need for an opening device having a high efficiency in regard of the amount of material used and the time needed for production of each opening device.